Noninvasive and unobtrusive instrumentation is needed to monitor individuals in clinical and natural settings for such purposes as monitoring for medication side effects, monitoring post-operative and chronic patients, and for diagnosing and treating various disorders. Example disorders include sleep problems (e.g., sleep/wake patterns; sleep quality, quantity, and circadian phasing; sleep disordered breathing), pain management, and ADHD. A significant problem encountered in such applications is the lack of an accurate "wear and forget" device that can be worn discreetly and comfortably for long periods to measure physical activity and physiological parameters. The proposed research focuses on the development of a novel, integrated, high-accuracy, body worn System for Monitoring Activity, Respiration, Heart rate, and Temperature (SMARHT). The SMARHT represents a one-piece sensor system that maximizes ease of use and wearer comfort. It avoids the ergonomic problems associated with conventional ambulatory measurements, such as chest belts or adhesive EGG electrodes used to measure heart rate, and chest band inductive plethysmographs used to measure respirations. Phase I work will demonstrate a better method for wirelessly collecting such physiological data. The effort will include validation testing of SMARHT recorded physical activity and physiological data collected on human subjects at rest and while performing a wide range of activities.